SelectWithUnionQuery (children 2)
 ExpressionList (children 1)
  SelectQuery (children 4)
   ExpressionList (children 1)
    Function count (children 1)
     ExpressionList (children 1)
      Asterisk
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier tab
   Function equals (children 1)
    ExpressionList (children 2)
     Identifier b
     Function rand64 (children 1)
      ExpressionList
   Set
 Identifier Null
